USDA Hardiness Zone 7a
Frost Dates for 42103 — Bowling Green, Kentucky
NOAA 1991–2020 normals from Bowling Green Warren Co Airport, KY (523 ft), 2 miles west.
Updated
In Bowling Green, the last spring frost (32°F) is around April 5 in half of years and has passed by April 21 in nine years out of ten. The first fall frost comes around October 31, as early as October 20 one year in ten, leaving a typical freeze-free season of 208 days (NOAA, Bowling Green Warren Co Airport, KY).
- Last spring frost
- April 5
- First fall frost
- October 31
- Growing season
- 208 days
- Hardiness zone
- 7a
50% probability
50% probability
freeze-free, 50%
0 to 5°F (-17.8 to -15.0°C) coldest night
- First snow
- December 28
- Last snow
- February 23
- Winters with snow
- 100%
- Snow per year
- 8.5"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Bowling Green
Half of springs at Bowling Green Warren Co Airport, KY see their last 32°F night by April 5; only one in ten is past it by March 20, and one in ten still has one after April 21. Planting tender crops after April 11 leaves a 30% risk of a frost on them, after April 15 20%, and after April 21 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 68% of the 113 Kentucky stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 31 in half of years, as early as October 20 one year in ten, and holds off past November 11 one year in ten. A hard freeze of 28°F follows 10 days later, around November 10; in spring the one-in-ten date for 28°F is April 7, 14 days before the 32°F one. The freeze-free season lasts 208 days in a typical year, longer than at 83% of the 113 Kentucky stations; it reaches 229 days one year in ten and falls short of 187 one year in ten. On average 82 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 11 days longer, to about April 16, and return around October 22. Severe cold of 16°F or below comes in 99% of winters, usually between December 24 and February 10.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 2 | Apr 7 | Apr 10 | Apr 13 | Apr 16 | Apr 19 | Apr 24 | Apr 28 | May 4 |
| 32°F | Mar 20 | Mar 26 | Mar 31 | Apr 2 | Apr 5 | Apr 8 | Apr 11 | Apr 15 | Apr 21 |
| 28°F | Mar 4 | Mar 12 | Mar 16 | Mar 20 | Mar 24 | Mar 27 | Mar 30 | Apr 2 | Apr 7 |
| 24°F | Feb 20 | Feb 28 | Mar 3 | Mar 6 | Mar 10 | Mar 14 | Mar 18 | Mar 22 | Mar 29 |
| 20°F | Feb 2 | Feb 10 | Feb 15 | Feb 22 | Feb 27 | Mar 2 | Mar 5 | Mar 10 | Mar 16 |
| 16°F99% of yrs | Jan 17 | Jan 28 | Feb 1 | Feb 5 | Feb 10 | Feb 16 | Feb 22 | Feb 28 | Mar 7 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 9 | Oct 14 | Oct 17 | Oct 20 | Oct 22 | Oct 24 | Oct 26 | Oct 30 | Nov 2 |
| 32°F | Oct 20 | Oct 23 | Oct 26 | Oct 29 | Oct 31 | Nov 1 | Nov 4 | Nov 7 | Nov 11 |
| 28°F | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 15 | Nov 19 | Nov 25 |
| 24°F | Nov 6 | Nov 11 | Nov 14 | Nov 17 | Nov 20 | Nov 24 | Nov 28 | Dec 2 | Dec 8 |
| 20°F | Nov 15 | Nov 22 | Nov 26 | Dec 1 | Dec 4 | Dec 8 | Dec 14 | Dec 22 | Dec 30 |
| 16°F99% of yrs | Nov 30 | Dec 5 | Dec 11 | Dec 18 | Dec 24 | Dec 28 | Jan 1 | Jan 8 | Jan 18 |
Freeze probabilities 1991–2020 at Bowling Green Warren Co Airport, KY, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 42103 →Compare Bowling Green with another place →
Weather by month in Bowling Green
July is the warmest month at Bowling Green Warren Co Airport, KY, averaging 90°F by day and 70°F at night; January is the coldest at 46°F and 28°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 64% of years.
Warmth for growing adds up to 4,705 growing degree days a year (base 50°F), more than at 94% of the 113 Kentucky stations. 38% of them (1,805) have built up by the end of June, and July adds the most, 921. Precipitation totals 50.0 inches a year, most in May (5.0") and least in January (3.6"); May to September bring 43% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 46 | 28 | 3.6 | 100% | 21 | 23 |
| Feb | 51 | 31 | 4.1 | 100% | 17 | 34 |
| Mar | 60 | 38 | 4.5 | 98% | 10 | 114 |
| Apr | 71 | 47 | 4.8 | 64% | 2 | 295 |
| May | 79 | 57 | 5.0 | 2% | 0 | 557 |
| Jun | 87 | 66 | 4.5 | 0% | 0 | 783 |
| Jul | 90 | 70 | 4.3 | 0% | 0 | 921 |
| Aug | 89 | 68 | 3.9 | 0% | 0 | 883 |
| Sep | 83 | 60 | 3.6 | 0% | 0 | 643 |
| Oct | 72 | 48 | 3.6 | 53% | 2 | 327 |
| Nov | 59 | 38 | 3.7 | 100% | 11 | 93 |
| Dec | 49 | 32 | 4.4 | 100% | 18 | 32 |
Monthly normals 1991–2020 at Bowling Green Warren Co Airport, KY (523 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Mammoth Cave, KY, 17 miles northeast of Bowling Green and 237 feet higher, has a last frost 4 days later (April 9), a first frost 1 day earlier (October 30), a season 4 days shorter.
When it snows in Bowling Green, Kentucky
The first measurable snow (0.1 inch or more) in Bowling Green usually arrives around December 28, and the last of the season around February 23. Those are the middle dates across the winters of 1991–2020 at Bowling Green Warren Co Airport, KY, 2.3 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 41 days after the last snow.
Planting calendar for 42103
| When | What to do |
|---|---|
| January 25 – February 8 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 8 – February 22 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 8 – March 22 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 5 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 8 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 17 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 31 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 42103 is 2 miles from Bowling Green Warren Co Airport, KY, which stands at 523 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 42101 (Bowling Green). The 2023 USDA Plant Hardiness Zone Map lists ZIP 42103 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.